Processes for making reliable VCSEL devices and VCSEL arrays

A process of fabricating a VCSEL device wafer comprising the steps of:

• providing a semiconductor substrate;
• growing in a pre-determined sequence, a stack of one or more epitaxial layers of semiconductor material on one surface of the semiconductor substrate, wherein said step of growing the stack of one or more epitaxial layers includes configuring at least a first reflector, a gain region, an oxidizing layer proximal to the gain region and a second reflector according to a pre-determined design of a VCSEL device structure for a desired output characteristics;
• growing a strain compensation layer on a second opposing surface of the semiconductor substrate to a pre-determined thickness, such that the VCSEL device wafer including the semiconductor substrate, the one or more epitaxial layers and the strain compensation layer is substantially free of bow and/or warp;
• etching a plurality of mesas of a pre-determined size and to a pre-determined depth not to exceed the thickness of the stack of one or more epitaxial layers;
• oxidizing the oxidation layer to a pre-determined width from the edge towards the center of the plurality of mesas, thereby creating within the plurality of mesas, a respective plurality of apertures, each smaller than the size of the corresponding mesas;
• and
• applying metal contacts to a pre-determined first and second layers for providing respectively, first and second electrical connections to the VCSEL device structure.